I thought that I was able to use my mouse to navigate in the viewport before. I can only seem to rotate the project view via the numpad keys. I have tried to Google for my problem but can not seem to find any answers.
You can try one of the following
- View > View selected or . on Numpad
- If that doesn't work try Shift + C
It seem that with some blend files "zooming to much" locks the 3D view and you can only rotate the view, not pan or zoom in or out, with other .blend files it is OK... don't know the real source or how to fix the file, anyway if you still want "free zoom, pan and rotate", you can copy the objects that you need to a new .blend.
If you're using Razer products for peripherals, you will need to open up Razer Synapse and change your middle mouse button from left click to scroll click, save your profile configuration and try this again in the 3d viewing window. Other Manufacturers that do not use the windows default drivers but rather their own software may have a similar problem with their configuration/keybind. Hope this helps, took me 30 minutes to think of.